Polymer compositions with improved surface properties

Abstract

This invention relates to a composition and method of modifying the surface properties of polymers to produce a film or article with improved surface properties by utilizing an organo-modified polyslioxane additive. The improved surface properties for the polymer include a reduced coefficient of friction, which assists the slip and anti-blocking properties of the material, as well aiding in processing of the polymeric material. Additionally, the additive composition of this invention improves demolding and release of the polymer material from other polymeric surfaces or adhesives as well as metal molding surfaces, and allows the entire film or article formed of the polyolefin and additive to be recycled.

I claim: 
     
       1. A polymer composition having improved surface properties, the composition comprising:
 a) a thermoset resin polymer; and 
 b) at least one melt processable, organo-modified siloxane additive capable of reducing the COF of the polymer composition of the formula:
   R—SiR 1   2 —[O—SiR 1 R 2 ] x —[O—SiR 1 Z] y —O—SiR 1   2 —R
 
 
 
       in which
 Z is a radical with the structure —[O—SiR 1 R 2 ] n —O—SiR 1   2 —R 
 R is a hydroxyl or methyl radical; 
 R 1  is a methyl radical; 
 R 2  is selected from the group consisting of a C1 or a C12-C75 saturated or unsaturated, hydrocarbon radical; 
 x is greater than 15; 
 y is 0-50; and 
 n is 0-50 
 
       wherein at least 10% of the siloxane units present in the additive compound are not di-methyl siloxanes, and wherein the remainder of the siloxane units are di-methyl siloxanes. 
     
     
       2. The polymer composition of  claim 1  wherein at least 75% of the siloxane units present in the additive compound are not di-methyl siloxanes. 
     
     
       3. The polymer composition of  claim 1  wherein the additive is present in an amount of between about 0.01 to about 10 parts by weight of the composition. 
     
     
       4. The polymer composition of  claim 1  wherein x is greater than 35 and at least 50% of the R 2  groups are alkyl groups of C16 to C75. 
     
     
       5. The polymer composition of  claim 1  wherein the improved surface properties are selected from the group consisting of: a coefficient of friction, slip properties, blocking properties, demolding capability, release properties, and combinations thereof. 
     
     
       6. The polymer composition of  claim 1  wherein the polymer is filled or unfilled. 
     
     
       7. The polymer composition of  claim 1  wherein the non-methyl R2 groups are C18-C75 saturated or unsaturated, hydrocarbon radicals. 
     
     
       8. The polymer composition of  claim 1  wherein the non-methyl R2 groups are C22-C75 saturated or unsaturated, hydrocarbon radicals. 
     
     
       9. The polymer composition of  claim 1  wherein the composition is fully recyclable. 
     
     
       10. The polymer composition of  claim 1  wherein the composition is formed into a release liner. 
     
     
       11. A method for improving the surface properties of a polymer composition formed of a thermoset resin polymer which comprises adding to the polymer between about 0.01 to about 10 parts by weight of the composition of an additive of the formula:
   R—SiR 1   2 —[O—SiR 1 R 2 ] x —[O—SiR 1 Z] y —O—SiR 1   2 —R
 
 
       in which
 Z is a radical with the structure —[O—SiR 1 R 2 ] n —O—SiR 1   2 —R 
 R is a hydroxyl or methyl radical; 
 R 1  is a methyl radical; 
 R 2  is selected from the group consisting of a C1 or a C12-C75 saturated hydrocarbon radical; 
 x is greater than 15; 
 y is 0-50; and 
 n is 0-50 
 
       wherein at least 10% of the siloxane units present in the additive compound are not di-methyl siloxanes, and wherein the remainder of the siloxane units are di-methyl siloxanes. 
     
     
       12. The method of  claim 11  wherein the surface properties are coefficient of friction, release properties, demolding properties, blocking properties and slip properties. 
     
     
       13. The method of  claim 11  wherein the additive present in the polymer compound improves the filler and pigment dispersion resulting in improved processing and improved physical properties of the compound. 
     
     
       14. A polymer composition having improved surface properties, the composition comprising:
 a) a thermoset resin polymer; and 
 b) at least one melt processable, organo-modified siloxane additive capable of reducing the COF of the polymer composition of the formula:
   R—SiR 1   2 —[O—SiR 1 R 2 ] x —[O—SiR 1 Z] y —O—SiR 1   2 —R
 
 
 
       in which
 Z is a radical with the structure —[O—SiR 1 R 2 ] n —O—SiR 1   2 —R 
 R is a hydroxyl or methyl radical; 
 R 1  is a hydroxyl or methyl radical; 
 R 2  is selected from the group consisting of a C1, an alkoxylate or a C12-C75 saturated or unsaturated, hydrocarbon radical; and 
 x is greater than 15; 
 y is 0-50 
 n is 0-50 
 
       wherein at least 10% of the siloxane units present in the additive compound are not di-methyl siloxanes, and wherein the remainder of the siloxane units are di-methyl siloxanes, and wherein if R 2  is an alkoxylate the percent of non-dimethyl siloxane groups that contain the alkoxylate is between 5 to 75%.